Comparison of Intraspinal Nerve Root Stimulation With Dorsal Column Stimulation

Inclusion Criteria: * Have chronic low back pain following spine surgery (Failed Back Surgery Syndrome. * Be an appropriate candidate for Spinal Cord Stimulation (SCS) and for the surgical procedures required for SCS. * Have experienced significant though short-lived pain relief with local anesthetic injection. * Be 18 years of age or older. * Be willing and able to comply with all study related procedures and visits. * Be capable of reading and understanding patient information materials and giving written informed consent. Exclusion Criteria: * Have any significant medical condition that is likely to interfere with study procedures. * Have any evidence of neurologic instability. * Have any other chronic pain condition. * Have a condition currently requiring or likely to require the use of MRI or diathermy. * Have an active implantable device. * Are pregnant or planning to become pregnant in the next year. * Are a current substance abuser (including alcohol and illicit drugs). * Have a significant psychiatric disorder. * Have participated in any drug or device trial in the last 4 weeks or plan to participate in any other trial during the duration of this study.